July 29, 2013

Patterns of two giant surfactant samples in thin-film state (credit: PNAS)

University of Akron researchers have developed nanoscale “giant surfactants” (using nanopatterning to combine functioning molecular nanoparticles with polymer surface films and liquid solutions) that could lead to smaller chips, lighter laptops, slimmer televisions, and crisper smartphone visual displays.

Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid.

The giant surfactants developed at UA are large, similar to macromolecules, yet they function like molecular surfactants on the nanoscale, Cheng says. These nanostructures can guide the size of electronic products.

More efficient designs possible

Nanopatterning, or self-assembling molecular materials, is behind the small, light, and fast world of modern-day gadgetry, and now it has advanced one giant step, the UA researchers suggest. When these new materials are integrated into electronics, they will enable development of ultra-lightweight, compact and efficient devices because of their unique structures, say the UA researchers.

During their self-assembly, molecules form an organized lithographic pattern on semiconductor crystals, for use as integrated circuits. According to Stephen Z.D. Cheng, dean of UA’s College of Polymer Science and Polymer Engineering, these self-assembling materials differ from common block copolymers (a portion of a macromolecule, comprising many units, that has at least one feature which is not present in the adjacent portions) because they organize themselves in a controllable manner at the molecular level.

“The IT industry wants microchips that are as small as possible so that they can manufacture smaller and faster devices,” says Cheng, who also serves as the R.C. Musson and Trustees Professor of Polymer Science at UA.

He points out that the current technique can only produce chip spacing of down to 22 nanometers, and cannot go down to the 10 nanometers or less necessary to create tiny, yet more powerful devices. The giant surfactants, however, can dictate smaller-scale electronic components.

“This is exactly what we are pursuing — self-assembling materials that organize at smaller sizes, say, less than 20 or even 10 nanometers,” says Cheng.

Commercial applications

An international team of experts, including George Newkome, UA vice president for research, dean of the Graduate School, and professor of polymer science at UA; Er-Qiang Chen of Peking University in China; Rong-Ming Ho of National Tsinghua University in Taiwan; An-Chang Shi of McMaster University in Canada; and several doctoral and postdoctoral researchers from Cheng’s group, have shown how well-ordered nanostructures in various states, such as in thin films and in solution, offer extensive applications in nanotechnology.

The team’s study is highlighted in a pending patent application through the University of Akron Research Foundation and in Proceedings of the National Academy of Sciences.

“These results are not only of pure scientific interest to the narrow group of scientists, but also important to a broad range of industry people,” says Cheng, noting that his team is testing real-world applications in nanopatterning technologies and hopes to see commercialization in the future.